What are the requirements and procedures for obtaining a 1-year extension based on marriage to a Thai wife at Chaeng Wattana immigration office?

Seeking advice about the 1 year extension based on having a Thai Wife - at ChaengWattana.

* Is booking required, or are walk-ins also accepted? First available booking on the website is 3 Jan, I need to apply on 6 or 9 December. Is it better to arrive early to be at front of queue, or are afternoons quieter?

* does anyone have a recent copy of the document checklist they could provide me. I've been working of Phitsanulok checklist, so not sure what requirements would be different.

* For the B400,000 statement and letter from the bank, can that be from a few days before the application, or do I have to get something from the bank on the morning of application

* Does the KorRor22 have to be printed same day as application, or can be earlier? Phitsanulok office require it printed same day as the application.

* How much notice do they normally give before home visits? What if you are out at the shops, visiting friends, restaurant, etc?

For reference - I'm on an Australian passport, with Non-Imm O visa. Current entry stamp expires 9 December, visa stamp is already expired. Married to Thai wife. We tried to apply today at Phitsanulok immigration, since we are currently staying there, however, have been sent to apply at Bangkok immigration since that is our more primary residence (we alternate between both locations frequently) and were planning to be there most of December.

Phitsanulok immigration said there would be 3 home visits during the 30 day under application period, and at least 1 would be unannounced, and if we were not home when they turned up the whole visa would simply be cancelled.

Any advice appreciated, as I'd like to avoid multiple trips out to ChaengWattana.